eChapters

7.1 Introduction

Food processing has become one of the most competitive sectors in recent years. With increasing consumers’ demands, food industry needs to keep updating technology. These efforts are focussed at improving the organoleptic quality and nutrition of food and improve its keeping quality. This drives the industry to look for newer technologies which include new products as well as new processes. Some of the new processing technologies include non-thermal processes such as high pressure processing, pulsed electric fields and ultrasound processing. Advanced thermal processing techniques such as ohmic heating, inductive heating, extrusion and infrared heating have also been developed. Innovative methods for improving food quality through irradiation, removal of heat and moisture from food are now available. Newer packaging techniques now help to improve shelf-life and attractiveness of the food products and cater to the biodegradability of the packaging material. Hence, there is abundance of new products that have now become part of our daily life.

Food nanotechnology has its long history when the first step of revolution in food processing and improvement in quality of foods was introduced by Pasteur to kill the spoilage bacteria (1000 nm). Later, Watson and Crick’s model of DNA structure, which is about 2.5nm, opened the gateway of applications in biotechnology. Nanotechnology is defined as the design, production, and application of structures, devices, and systems through control of the size and shape of the material at the nanometer (10^-9 of a meter) scale. Nanotechnology is one such technology that has the potential to revolutionize the food industry. Taniguchi first used nanotechnology in 1974 to describe production technology at ultrafine dimensions. The word “nano” means “dwarf” in Greek and one nanometer is equivalent to 10^-9 m. Objects of this scale are not visible through the human eye or the ordinary optical microscope. A nanometer (nm) sized particle measures one billionth of a meter. A human hair measures 80,000 nm while a DNA strand is 2.5 nm wide whereas a protein chain is 5nm in diameter. Nanotechnology can be applied to develop nanoscale materials, controlled delivery systems, contaminant detection and to create nanodevices for molecular and cellular biology. Nanotechnology may be defined as the understanding and management of matter at dimensions of roughly 1-100 nanometers. Unique behavior of matter at the nanoscale enables novel applications. Nanoscale science, engineering, and technology can be used for imaging, measuring, modeling, and manipulating matter at this length scale. Range of sizes of nanomaterials in the food sector and their relative position on nanoscale/microscopic scale are listed below.

6.1 Introduction

Consumer demand, regulatory guidelines and economic power of the consumer as well as ascertained profitability stimulated the need of novel food processing techniques. The concept of “fresh”, “natural”, or “organic” food also led to the development of environmentally sound and resource efficient food processing technologies. Thermal processes have been used for food preservation since a long time. These are not very energy efficient and can change the phase of food from fresh to cooked as well as it can alter the nutritional and sensory qualities. Thus, the quest for energy conservation by the manufacturers to reduce carbon footprint of the processes involved in food processing and preservation as well as to fulfill consumers’ requirement for fresh-like quality food have given rise to the development of innovative non-thermal food processing technologies i.e. ionizing radiation, high-intensity light pulses, high isobaric pressure, electric or oscillating magnetic fields, as well as pulsed electric fields (PEF).

Application of electric energy in food processing started in the early 1900s. In the beginning, electrical pasteurization inactivated microorganisms by increasing the temperature of samples by means of an electrical resistance (ohmic heating). Milk was the first electrically pasteurized product. In the late 1940s, electric fields were used to increase the permeability of fruits to facilitate the subsequent extraction of juices. The PEF technology as a non-thermal process is very effective for inactivation of microorganisms, increasing the pressing efficiency, enhancing the juice extraction, and for intensification of the food dehydration and drying process. The main effect of PEF technology is based on the phenomena that biological membranes are punctured under the influence of external electrical impulses. This process is often referred as non-thermal, since the structural damage to membranes is implemented at very low temperature compared to the conventional heating process. The PEF process is considered to be energy efficient because the electric energy is released in short pulses, thus total energy requirement is much lower than other continuous preservation technologies. The microbial inactivation can be achieved at ambient or moderately elevated temperatures by the application of short-bursts of high intensity electric fields to liquid foods flowing between two electrodes or to semi-solid/ solid food between some specialized electrode and treatment systems. Due to chemical/physical properties and presence of electrical charge, the liquid foods (e.g. milk or fruit juices) had different conductivity, which results in variable flux of electrical current through the food systems.

5.1 Introduction

Food is the basic requirement of every living being and it provides physical, mental as well as emotional satisfaction. Globally, there are many food enterprises which provide this basic necessity across the nations irrespective of nature of origin and climatic condition. Food companies are required to provide products at certain quality parameters so as to maintain the uniformity in the food system. Hence, food quality can be defined as a total of traits and criteria which characterize food as regard to its nutritional value, sensory value, convenience as well as the safety for a consumer’s health. Food quality is the quality characteristics of food that is acceptable to consumers. This includes external factors as appearance (size, shape, colour, gloss and consistency), texture, and flavor; factors such as grade standards and internal (chemical, physical, microbial). Due to the various food risks, all over the world the quality regulation authorities have intensified the efforts to improve food quality. Some of the quality related systems are obligatory by law while other is voluntary which are to be implemented by the various food chain members.

Many companies are forced to improve safety and quality of their products by implementing the quality and safety assurance and management system because of growing consumers’ expectations and concerns as regards food quality and safety.

In order to attain maximum profit and decrease the flaws, a new system was developed and followed by various companies all over the world. This new system is known as Six Sigma. The application of this system has the capability to reduce the losses considerably by reviewing the process parameters and increasing the profit exponentially. It constitutes a systematic approach to assure that food products have particular traits at any stage of production and distribution.

4.1 Introduction

The purpose of processing the food is to make it safe and healthy for human consumption. The term food processing refers technologically anything, which transforms raw ingredients into consumer ready products, with the aim of stabilizing food products by preventing or reducing deteriorative changes in quality. The objective of food manufacturers is to develop, modify and employ those processing technologies that retain or create desirable sensory qualities in food and eliminate or reduce undesirable changes due to processing.

The purpose of food processing is to increase the shelf life of food before spoiling (preservation); to remove, destroy or inhibit pathogens and toxins (food safety); to change flavor, texture, aroma, color or form (variety); to reduce preparation times and make food more portable (convenience); to restore and/or raise nutrient levels in food (nutrition).The various food processing methods used extensively in food industry include physical (high temperature, freezing, chilling, dehydration, packaging), chemical (control of storage gases, reduction of water activity, pH, addition of chemical additives or spices) preservation methods.

Traditionally, food preservation has been associated with thermal treatments alone or in combination with biochemical or chemical methods. For example, the thermal processing of milk is done various thermal treatments viz. at 63^oC for 30 min for low temperature long time (LTLT), 72^oC for 15 seconds for high temperature short time (HTST) pasteurisations and up to 140^oC for a few seconds for ultra high temperature (UHT) treatment. However, such thermal treatments effectively reduce level of microorganisms but in long-term preservation, it may lead to losses of desired organoleptic attributes and destruction of temperature liable nutrients and vitamins. The limitations involved with thermal processing has been overcome by employing chemical preservation, cool chain management and process hygiene in the formulation and production of food products.

3.1 Introduction

Energy comes in many forms like chemical, radiant, mechanical, electrical, nuclear etc and can transform from one type to another. Energy can also be transferred or moved from one object to another. Electromagnetic (EM) radiation is a form of energy that can take many forms, such as radio waves, microwaves, X-rays and gamma rays even sunlight is also a form of EM energy. Visible light is a small portion of the EM spectrum, which contains a broad range of electromagnetic wavelengths.

Electromagnetic waves, a self –propagating transverse radiation, are created when an atomic particle, such as an electron, is accelerated by an electric field, causing it to move. The movement produces oscillating electric and magnetic fields. The electric and the magnetic components of the wave are perpendicular to each other and also perpendicular to the direction in which wave is travelling in a bundle of light energy called a photon. Photons travel in harmonic waves at the fastest speed possible in the universe: 186,282 miles per second (299,792,458 meters per second) in a vacuum, also known as the speed of light. There are three important characteristics of the electromagnetic radiation, its frequency, amplitude and speed (Figure 3.1).

2.1 Introduction

Food is one of the complex systems involving many constituents such as carbohydrates, lipids, proteins, vitamins, minerals and other phytochemicals. These all constituents are not present in the same relative proportion in every type of food and thus the foods are categorized and valued according to the presence of these constituents as protein rich foods, fat rich foods, etc. The specific type of food is in abundance with only one or at most two of these constituents and rest of the bulk is not valuable, commercially. So, if these active constituents which are present in the tissue surrounding inactive matrix, are separated, it is of great benefit with respect to increased purity, nutritive value, functional properties, reduction in volume, easy handling and transportation. On contrary some valuable food items contain undesirable constituents generally referred as anti-nutritional factors. Removal of these anti-nutritional factors enhances the food value and commercial utilization. Hence, the separation of phytochemicals and removal of anti-nutrients from the food matrices can be easily carried out by using a unit operation called as extraction.

Extraction involves the separation or isolation of active/desirable components of complex system viz., plant and animal tissues from the rest of inactive/undesirable components by using suitable means such as solvent or mechanical structure. The basic principle involved in the extraction process is partitioning of different components in accordance with the extracting agent. For example, in mechanical extraction, the partitioning is due to pressure and screen/apperature size where as in case of solvent extraction, the portioning of components from mixture takes place due to particular solubilizing power of solvent used.

1.1 Introduction and Background

In present scenario, the word “extrusion” refers to a process by which dry or semi-moist ingredients with varying in-barrel moisture are forced through varying barrel temperature, screw speed and screw configuration through a die opening of the desired cross section. In other words, extrusion is predominantly a thermo-mechanical processing operation that combines several unit operations, including mixing, coating, kneading, venting, shearing, heating, forming, partial drying or puffing, depending on the material and equipment used.

The origins of extrusion are in the metallurgical industry, where in 1797 Joseph Bramah patented the first extrusion process, wherein a piston driven device was used for making seamless lead pipes. The present understanding of extrusion technology and the developments or improvements in machine design are largely due to research carried out by the plastics industry. In food industry, this technology is in use since 1930 and its popularity is increasing continuously due to its efficiency, continuity and sustainability. In beginning, sausage extruders were developed in the nineteenth century as simple forming machines. One of the original developments which laid the foundation of the food extrusion was the use of pasta press termed as “cold extruder” in mid 1930s. Furthermore, in the late 1930s, General Mills, Incorporation., Minneapolis, MN, USA, first used a single screw extruder in the manufacture of ready-to-eat (RTE) cereals. Later in 1970s, twin screw extruders were used for the manufacture of moist pet-foods. Twin screw extruders were also adapted from polymer industry, as rising food quality and limitations of single screw extruders were demanding a more versatile process for the newer and higher quality products. After 1970s, the extrusion processing with simultaneous use of heat was popularized as a versatile and highly energy efficient with negligible wastage process. In all these years, number of changes has been noted in the extruder design such as changes in screw design, barrel design and also material used for the manufacture of these materials. Barrel liners availability along with already available segmented screws could further add more economics to the process and increased equipment lifetime. For better wearing characteristics, a number of screw elements of different materials are being used in addition to standard nitrided steel for customized processing needs, such as corrosion and wear resistant surface coated steels, stainless steel, satellite welded and bimetallic HIP (Hot Isostatic Press). JBL Feedscrews Limited, a UK based company recently introduced tungsten carbide coated screw in conjunction with a compatible bimetallic barrel. Likewise, a number of options for barrel metallurgy are available to withstand the higher internal pressure and temperature. Barrels lined with hard cobalt based alloy, typically Xaloy, to give abrasion and chemical resistance are also in use, although, the most common material is carbon steel with a nitride interior. Similarly, steam heated or jacketed barrels were used earlier for cooking purpose which gradually replaced by the electric induction heating elements. These HTST cooking extruders are versatile, highly productive and energy efficient processing machines. They can use a wide variety of raw materials and formulations to produce products with increased shelf-life and convenience.

ABSTRACT

Granite in the present day context is popularly known as the principal raw material in construction industry and also known for its value addition product as Dimension Stone in the global market. India is in pride possession of much sought granite varieties of the world. No doubt the demand for such granite varieties is quite high both for local and export markets but in reality the failure rate of granite quarries is also high, The technical reasons attributed for such failures being lack of application of proper scientific skill both in selection and mining ofgranite deposits. The past experience in the fieldof granite exploitation has thought us a lesson for application of geological knowledge in selection of right deposits and in adopting the right techniques. The selection criteria for construction purpose and for export market though looks simple, is more complicated in the case of dimension stone granite deposits, the reasons being the requirement of thorough knowledge in petrography,structure,geotechnical characters of the deposit. Considering the importance of the scientific knowledge, the present paper focuses on the various parameters for valuation of granite deposits. In other words, it emphasizes on arriving at a logical conclusion by applying the scientific knowledge in successful exploitation of the much valued granite deposits.

ABSTRACT

The present work relates to geological and commercial aspects of pyroxene syenite (Green Onyx) occuring in and around Sivamalai of Periyar District in Tamil Nadu. The alkaline complex of Sivamalai comprises syenites-, nepheline syenite and their variants. Pyroxene syenite is possibly the oldest within the syenite complex occurring as minor massifs, elongated linear bodies, -arcuate islands and enclaves within feldspar syenite are observed in the hillocks North East of Sivamalai, namely Chennimalai and its southern extensions. On the commercial point of view, the pyroxene syenite in the study area occupies nearly 30 square -kilometres area and can be categorised as Kalleri Block, Neykkarampalayam Block and Sivamalai Block. The observed petrographic and petrochemical characters of the alkaline rocks of the study area favours magmatic origin for these rocks. A detailed geological study and random market survey of individual syenite bodies proved the true worthiness of the material Green-Onyx as a dimensional stone with substantial resources and market potential.

INTRODUCTION

Remote Sensing is an indigenous tool for the Environmental Impact Assessment study. It plays vital role in preparing various thematic maps for understanding the changes that have taken place in an area before and after the establishment activities. In this study we have utilized the capability of the remote sensing techniques in understanding the mining environment. Our study area is in and around the Dalmiapuram Cement Industry in the central part of Tamil Nadu state and it covers part of Trichy and Perambalur districts. It falls between 11₀ 02’ 42’’and 1₀ 03’ 08’’E and 79₀ 09’ 39’’and 79₀ 10’ 30’’N.Dalmiapuram Cement Industry is located in the Kovandakurichi village of Pullambadi block, Trichy district. The mines for cement manufacturing are Perianagalur (PNR), Periathirukonam (PTK), Kallakudi (KLK), Kovandakurichi (KVK) and A&K Mines.

The litho units are Limestone beds containing various proportions of bioclastic and siliciclastic materials. They show wackstone to rudstone fabric and have clasts of re-deposited bound stones. Deposition in a periodically restricted shallow marine setting was indicated by lithological and faunal information. Lower contact is an unconformity surface associated with marine flooding and the upper contact is non-depositional and erosional with overlying biostormal member.

ABSTRACT

In order to assess the baseline environmental status in the PTK mines the comprehensive primary data collection / survey programme was undertaken during the period i.e. from April 2003 to June 2003. The environmental monitoring for ambient air quality, water quality, soil quality, noise levels, dust fall, traffic density, meteorology of the study area, etc was carried out. Detailed satellite image interpretation was carried out and thematic maps of the study area were prepared by visual interpretation using tone, texture variations from IRS –IC LISS-III – False Color Composite geo coded images. Digital image processing techniques (supervised classification) were used to classify land use, geology, geomorphology, and drainage pattern/ watersheds and soil cover of the study area. Detailed flora and fauna study was carried out in the study area comprising of core and buffer zones for identification of existing species. The description of baseline environment in the study area is given below.

ABSTRACT

The coastal zone is environmentally sensitive and economically valuable, which has great attention from researchers especially from geoscientists. Coastal zone has great threat from pollution and natural calamities like cyclones, flood and tsunami. Natural calamity is a frequent phenomenon over coast. Therefore, it is very essential to monitor the changes over coastal ecosystem and geomorphic features like beach, shoreline and sand dunes. In this case, one of the basic requirements in managing and monitoring these features is the topographic data. The recently emerged technique of Airborne Altimetric LiDAR provides accurate topographic data. It is in preparatory stage in India. By this technique, we can collect the data at high speed when disaster happens. This paper attempts to provide a general overview of the role of LiDAR in coastal management.

ABSTRACT

The present paper highlights the implication of geochemical strategic tools to choose suitable site selection on the coastal region. Geochemical tools and geomorphological survey have been also deployed to identify the suitable site. The geomorphology of the site A reveals enough fresh water accumulation was found and the two elevated crest and the adjacent trough (low land) with surrounding areas further support the fact. The water quality of this site exposes very good quality (< 200ppm TDS) and the dissolved major anions (HCO3, SO4, Cl) and cations (Ca, Mg, Na, K) concentration are well within drinking water standards. The soil samples are of medium to coarse sand nature showing high porosity (40 to 50%) with mica flakes acting as less permeable in nature. The water quality shows very good in nature and similar to Site A. The soil characters additionally proved good in porosity and permeability (SAR 1.5 to 2.1).

ABSTRACT

The use of Geographic information system to locate groundwater possible zone in Valapadi taluk of Salem was carried out using remote sensing and geophysical studies. The remote sensing methods involved in the visual interpretation of the satellite images for hydrogeomorphological and hydro structures favourable for groundwater. The geophysical method involved vertical electrical soundings to predict the sub-surface variation and to locate the water domain. Three geoelectric layers were delineated from the interpretation of vertical electrical sounding data and the map of the above results predict the depth extent of groundwater zone. The spatial distribution of the above results was identified through GIS.

ABSTRACT

A watershed is a topographically delineated area that is drained by a stream system, i.e. the total land area above some point on a stream or river that drains past that point. The watershed is a hydrologic unit that often is used as a physical – biological unit and a social – economic political unit for the planning and management of natural resources. Remote Sensing (RS) and Geographic Information System (GIS) techniques can be used effectively to generate the land use/land cover for evaluating the changes in an area. Conventional methods of runoff measurements are not easy for inaccessible terrain of Tamilnadu. Remote sensing technology can augment the conventional method to a great extent in rainfall-runoff studies. In this study, SCS Curve Number technique modified for Indian condition has been used for generation of CN for an ungauged watershed. A sub watershed of Manimuktha watershed is considered as study area. The daily rainfall data of Virudhachalam rain gauge station is collected and used to predict the daily runoff from the watershed using GIS based Soil Conservation Service -Curve Number (SCS – CN) method (USDA, 1972). Monthly and annual runoff values are obtained from the daily runoff values of the watershed. Base map, Soil map and Land use map of the study area are prepared by using Remote Sensing data and Survey of India (SOI) toposheets. PC Arc/Info GIS software is used for analysis.

ABSTRACT

The occurrence of fluoride more than permissible limit has been observed in ground water near Danishpet, Rajammannar Colony, Vayapurikombai, Melkombai, Umbilikampatty, Andikottai HC in Kadyampatty area, Salem district. Fluoride reaches to a maximum of 2.8 mg/l. Fluoride concentrations in ground water in various areas are as follows: Danishpet(2.0mg/l), Rajammannar Colony (2.8mg/l), Vayapurikombai (2.4 mg/l), Melkombai (2.4mg/l), Umbilikampatty (2.2 mg/l), and Andikottai HC (2 mg/l).. Granite gneiss and associated secondary vein filling minerals may be the source of high fluoride in ground water. The high concentration of Fluoride in ground water has led to human health hazard in the form of dental and skeletal deformation in the parts of Danishpet, Rajammar Colony, Vayapurikombai, Melkombai, Umbilikampatti and Andikottai HC villages.

ABSTRACT

The sources of fluoride in groundwater are minerals like fluorite, apatite, mica, amphiboles,cryolite and fluor.spar. The undue concentration of fluoride greater than 1 mg/l has befallen a major toxicological and geoenvironmental issue in India. Excess of fluoride in groundwater causes skeletal and dental fluorisis. The study area forms part of Salem district with records of endemic fluorisis. To decipher process and chemistry of fluoride, a total of 46 groundwater samples were collected from major litho units of the study area (Peninsular gneiss and Charnockite) and analyzed for fluoride using standard procedures for two seasons viz. pre and post monsoon. In pre-monsoon, maximum and minimum fluoride in Peninsular gneiss and charnockite were ranging from 2.85 to 0.4 mg/l and 4.02 to 0.37 mg/l respectively. The coresspnding figures in post monsoon ranges from 2.84 to 0.32 mg/l and 1.91to 0.37 mg/l respectively. Higher concentration was noted in charnockite folowed by peninsular gneiss in pre monsoon and the effect of dilution was well noted in post monsoon season. Statistical analysis undercovers the relationship of fluoride minerals with other ions. Modeling results represent the leaching of fluoride minerals and their variation along with seasons.

ABSTRACT

Microalgae in general and Cyanobacteria in particular are considered to be ideal biotechnological tools for their importance in the production of food, feed, fuel, fertilizers, fine chemicals and pharmaceuticals and their role in pollution abatement. So far, only 20 strains of microalgae have been cultivated for industrial purposes. To make use of more such organisms, it is essential to first identify their biodiversity in the naturally occurring populations and establish their germplasm for further characterization. With this in view, a detailed survey was made to study the biodiversity of Cyanobacteria in the Veeranam lake soil microflora in the Cuddalore district of Tamil Nadu. Influence of physico-chemical parameters habitat preferences of these soil microalgae, and their light and Electron microscopic features have been documented. The selected species of Cyanophyceae were subjected to energy dispersive spectroscopic analysis (EDS). They were found to accumulate different elements such as Zn, P, Mg, Ca, Mn, S and N. Thus these observations would determine the chemical dialogue between the cell structures and role of the elements. Further, it gives the clue about the soil microflora growth requirements.

ABSTRACT

Hydrogeochemistry of a region is a reflection of hydrodynamic process, composition of lithology and physical constraints. The water chemistry is the resultant of all biogeochemical processes and reactions, which have acted on water from the moment it has condensed in atmosphere till the time it is discharged. A case study has been carried out in a varied lithological terrain with Archean, Alluvium and Tertiary rocks to unravel the hydrogeochemical process. A geochemical model relays the distribution of mineral species in the groundwater. Geochemical modeling WATEQ4F has been carried out for pre-monsoon and monsoon period of various litho units in Gadilam river basin, Tamilnadu to find out the disequilibrium indices of carbonate (calcite, dolomite, magnesite and aragonite) and sulfate minerals (anhydrite and gypsum). The result of the model reveals that carbonate minerals show the over saturation state in monsoon period and the Sulfate minerals exhibit under saturation state in both the seasons.

ABSTRACT

The chemical characteristics of the groundwater in and around the Valapadi taluk of Salem district have been studied to evaluate the suitability of water for domestic and irrigation uses. Twenty three groundwater samples representing the shallow and deep aquifer of the area were collected and analyzed for pH, TDS, Ca, Mg, Na, K, HCO3, CO3, SO4 and Cl. It is observed that the quality of the groundwater is suitable for domestic use with some exception. The observed high quantity of Cl, SO4 and Mg at some places require immediate attention and detailed study. The value of EC and SAR indicate good to medium q of water for irrigation.